There are numerous different kinds of packs and pack frames in use to facilitate the carrying of loads on the back and other parts of the body. The pack with which we are concerned here is a so-called hip-level pack which is strapped around the waist like a belt and which includes one or more large bags or containers capable of supporting a relatively heavy load. The hip-level pack is particularly useful when one has to carry a multiplicity of articles for dispensing at different locations.
One obvious potential user of such a pack or pack frame is a paperboy who must carry a supply of rolled-up newspapers and deliver them door-to-door. Obviously, his job is simplified if he can carry a large number of such papers comfortably and yet remain mobile.
Another application which is of special interest here involves the planting of seedlings. After trees are harvested in a particular forest area, seedlings in the form of plugs are planted to provide replacement stock. While these plugs are quite small, it is often necessary for a worker to carry a large number of plugs with him when embarking on a planting operation. This is because the planting sites are often located in relatively inaccessible places remote from the seedling supply such that it would be uneconomical and time-consuming if the worker had to go back and forth frequently to replenish his personal supply of seedlings. Thus, while each seedling might weigh relatively little, it is not unusual for the supply of seedlings carried by a typical worker to weigh in the order of 50 lbs. or more at the beginning of a particular shift.
The most prevalent kind of hip-level pack in use today is shown generally at P in FIG. 1. It consists of a flexible belt B which is arranged to strap around the waist of the worker W. Attached to the section of the belt that extends around the worker's hips and back is a pair of relatively large flexible containers or bags P.sub.1 and P.sub.2 When the worker starts a shift, he fills the bags P.sub.1 and P.sub.2 with a multiplicity of seedlings S so that total weight of each bag and its contents can be as much as 25 lbs. At the planting site, the worker reaches back and withdraws seedlings S from the bags and, while bending over as shown in FIG. 1, digs holes in the ground and plugs the seedlings into the holes. Thus in the process of planting the seedlings, the worker must walk from place to place and constantly bend over and straighten up. When the worker is walking, he often has to jump or step over obstacles in his path. This action causes the pack P to bounce up and down placing considerable strain on the worker's hips and spine. Also, when the worker bends over, the pack P swings up as shown in FIG. 1 transferring the seedling load to the wearer's back and spine which over time causes additional fatigue and physical distress. In fact, people working in this field acquire a variety of orthopedic problems traceable directly to the way in which these heavy loads are carried on their bodies.
It would be desirable, therefore, to be able to provide a hip-level pack or pack frame which is relatively comfortable to wear and which distributes its load on the wearer's body so as to minimize orthopedic problems and yet which does not materially decrease the wearer's mobility and working efficiency.